Commercial use of real video conferencing was first realized with Ericsson's demonstration of the first trans-Atlantic LME video telephone call. Soon other companies began refining video conferencing technologies, including such advancements as network video protocol (NVP) in 1976 and packet video protocol (PVP) in 1981. None of these were put into commercial use, however, and stayed in the laboratory or private company use.
In 1976, Nippon Telegraph and Telephone established video conferencing (VC) between Tokyo and Osaka for company use. IBM Japan followed suit in 1982 by establishing VC running at 48000bps to link up with already established internal IBM video conferencing links in the United States so that they could have weekly meetings.
The 1980's introduce commercial video conferencing
In 1982, Compression Labs introduces their VC system to the world for $250,000 with lines for $1,000 an hour. The system was huge and used enormous resources capable of tripping 15 amp circuit breakers. It was, however, the only working VC system available until PictureTel's VC hit the market in 1986 with their substantially cheaper $80,000 system with $100 per hour lines.
In the time in between these two commercially offered systems, there were other video conferencing systems developed that were never offered commercially. The history of video conferencing isn't complete without mentioning these systems that were either prototypes or systems developed specifically for in-house use by a variety of corporations or organizations, including the military. Around 1984, Datapoint was using the Datapoint MINX system on their Texas campus, and had provided the system to the military.
In the late 1980's, Mitsubishi began selling a still-picture phone that was basically a flop in the market place. They dropped the line two years after introducing it. In 1991, the first PC based video conferencing system was introduced by IBM - PicTel. It was a black and white system using what was at the time an incredibly inexpensive $30 per hour for the lines, while the system itself was $20,000. In June of the same year, DARTnet had successfully connected a transcontinental IP network of over a dozen research sites in the United States and Great Britain using T1 trunks. Today, DARTnet has evolved into the CAIRN system, which connects dozens of institutions.
CU-SeeMe revolutionizes video conferencing
One of the most famous systems in the history of video conferencing was the CU-SeeMe developed for the MacIntosh system in 1992. Although the first version didn't have audio, it was the best video system developed to that point. By 1993, the MAC program had multipoint capability, and in 1994, CU-SeeMe MAC was true video conferencing with audio. Recognizing the limitations of MAC compatibility in a Windows world, developers worked diligently to roll out the April 1994 CU-SeeME for Windows (no audio), followed closely by the audio version, CU-SeeMe v0.66b1 for Windows in August of 1995.
In 1992, AT&T rolled out their own $1,500 video phone for the Home market. It was a borderline success. That same year, the world's first MBone audio/video broadcast took place and in July INRIA's video conferencing system was introduced. This is the year that saw the first real explosion in video conferencing for Businesses around the globe and eventually led to the standards developed by the ITU.
___________________________________________________________
好玩贺卡等你发,邮箱贺卡全新上线!
http://card.mail.cn.yahoo.com/
没有评论:
发表评论